Ok so this may sound like a dumb question but I am worried about not getting this new job. I am scheduled to have one of these done either Wednesday or Thursday and I had quite a lot to drink last night because my grandma passed after years of suffering with dementia and I was just down. Now I am scared I am going to fail this test. I don't know how long alcohol stays in the system or if they are just testing to make sure I didn't drink that day or what. Does anyone know how these tests work and how long alcohol stays in your system? I've looked it up and I've read 100 different answers.